Spatial oxygen gradients drive many cellular functions including cell migration, signaling, and differentiation. Sustained low oxygen tensions in tissue can impair the regenerative capacity and survival of tissue-engineered grafts. Therefore, the measurement of local oxygen concentration within a three-dimensional cell adherent scaffold is valuable in studying and tuning the dynamics of engineered graft success and integration.
Islet transplant will be a curative treatment for insulin dependent diabetes, not only increasing quality of life through reduced complications, but also decreasing the burden of self-management. In order for islet transplant to reach more patients with the benefits of normoglycemia, a number of challenges must be overcome. Encapsulation technology is rapidly developing, promising to be a part of the solution. From open porous scaffolds to diffusion barrier hydrogels, scaffolding and encapsulation materials can provide many desirable properties, including acting as a vehicle for therapeutic agents. The combination of multiple factors delivered in a temporally controlled fashion is likely to improve the long-term function of transplanted islets, defining a path toward greater future clinical success.
The Diabetes Control and Complications Trial (DCCT) established glucose control as an important factor in the progression of diabetic complications. Advances in insulin formulations and delivery methods since the discovery of insulin have made diabetes a chronic disease, with some patients having lived with the disease free of major complications for more than 50 years. However, the number of patients that can achieve complication preventative control despite using the best insulin self-management techniques and equipment available is limited and may be related to residual endogenous insulin production. The promise of tighter control by allowing pancreatic islets to perform their function has been the focus of intense research ever since the discovery that a transplant can cure a diabetic animal or human. Islet transplant is expected to be the major advance in clinical diabetes care following adoption of the closed loop artificial pancreas.
There is a long felt need in the art for compositions and methods useful for monitoring oxygen in tissue scaffolds and in transplants. The present invention satisfies these needs.